routes.MapRoute(
                name: "Admin",
                url: "admin/{action}/{id}/{param}",
                defaults: new { controller = "Admin", action = "Index", id = UrlParameter.Optional, param = UrlParameter.Optional }
            );

 [AdminAuthorizeAttribute]
    public class AdminController : Controller
    {
      .....

public class AdminAuthorizeAttribute : System.Web.Mvc.AuthorizeAttribute
    {
        protected override bool AuthorizeCore(HttpContextBase httpContext)
        {
            var id = (httpContext.Request.RequestContext.RouteData.Values["param"] as string)
                     ??
                     (httpContext.Request["param"] as string);
            if (id == "test")
            {
                return true;
            }
            return false;
        }
    }